SolutionsHydrolysis of Nitriles
1. Lengthening the chain
Propose a synthesis of pentanoic acid from 1-bromobutane.
- NaCN in a polar aprotic solvent (DMSO): SN2 gives pentanenitrile, CH3(CH2)3CN.
- Hydrolysis of the nitrile (HO−, heat) and acidification: pentanoic acid.
2. Lactic acid
How would you obtain 2-hydroxypropanoic acid from acetaldehyde?
Addition of cyanide (HCN/NaCN) to the aldehyde gives the cyanohydrin, CH3CH(OH)CN; its hydrolysis gives lactic acid, CH3CH(OH)COOH.